st: mahascore problem -- fixed

Thanks to the efforts of Kit Baum, a revision to -mahascore- in the
-mahapick- module has been placed on SSC.

-mahascore- and its related programs compute a Mahalanobis distance
measure. All users are advised to obtain the revision.
The problem in the old version (which I mentioned in a message on Dec
16) was that it could not properly handle a long varlist -- long in
terms of characters.